Start by chopping up the kale until it is almost minced.
Heat a saute pan over medium heat and olive oil. Add kale, salt, pepper and red pepper flakes and saute for 3-4 minutes. Add garlic, red wine vinegar and Dijon. You can add a splash of water at this point as well if more liquid is needed to keep it from sticking to the pan.
As kale sautes, combine egg yolk, Greek yogurt, Parmesan, salt and pepper in a bowl. Mix to combine.
When kale is done, turn off heat. Spoon a small amount of the kale mixture into the egg mixture to temper the eggs. Then pour the entire egg mixture into the pan with the kale. Turn heat back on to very low and let warm for 1-2 minutes.
Add pasta or spaghetti squash to pan and mix to combine.